moving. A couple of times it would all of the sudden start pulling real good. When I first start it and take off it runs a whole lot better then it go's into snall mode ! I get terrible gas milage also. I had a 2006 5.3 that was twice as fast. I'm not looking for a race truck it's the heavy laboring to get it to go and I know it can run better. Mic says no codes and it's ok.
My '07 is real sluggish and always having to go into passing gear to get it on 2007 GMC Sierra 1500
by jdflash1 in Potwin, KS on November 10, 2012
1 answer 1 comment
ANSWER by your.mechanic on November 11, 2012
see trans shop for advice
COMMENT by jdflash1 on November 12, 2012
Been there already. The shop said it was fine but could feel it laboring. Is there any way to make it run like it does in the morning before it warms up ? (closed loop)